A hyperfrequency diode structure, such as, for example, the PIN vertical structure diode, is already known, which operates at high frequencies and is provided with external connectors constituted by flat metallic beams affixed to the semiconductor chip in accordance with the so-called "beam-lead" technology. Such PIN diode, which is generally used as a switching or commutation diode connected in parallel or in series in a transmission line, is produced, for example, from an type N.sup.+ doped semiconductor substrate on which two mutually superimposed layers are formed by epitaxy, one of said layers, called "I layer", being made of a material having the highest possible resistivity, while the other layer is of the P.sup.+ type. A chemical attack (etching) is carried out, starting from the epitaxial layers and extending into the substrate up to a given depth, so as to create a cradle having, for example, a rectangular external contour, under which subsists a certain thickness of substrate material. This cradle is formed so as to delimit two semiconductor islets connected to each other by the substrate, one of said islets having, for example, a circular shape, while the other islet may be, for example, crescent-shaped, the circular islet being located opposite to the crescent-shaped one and at the center of the concave side thereof. The cradle is filled with dielectric material, such as glass, for example, and the P.sup.+ and I layers of the crescent-shaped islet are then eliminated by chemical attack. An anode contact is established by a first metallic beam which rests on the P.sup.+ layer of the islet and on the glass, and terminates in a cantilever fashion, while a cathode contact is established by a second metallic beam resting on the N.sup.+ substrate and being adapted to the crescent-shaped configuration thereof so as to define an ohmic contact, said second beam resting also on the glass and being terminated in a cantilever fashion.
Furthermore, with a view to being enabled to use such diode connected in parallel in a broad-band switching or commutation circuit, it is current practice, on the one hand, to endeavour to obtain zero impedance, or substantially zero impedance of the diode in direct diode polarity (or polarization) conditions, so as to achieve high isolation and, on the other hand, to endeavour to obtain a low capacitance in reversed polarity conditions, so as to be able to adapt the impedance of the diode to that of the environing hyperfrequency circuit; similarly, in the case of series connection of the diode in the commutation circuit, it is endeavoured to have substantially zero impedance in reversed polarity conditions and a low capacity in direct polarity conditions.
Now, it is well known that at the operating frequency of the diode the metallic beams introduce a parasitic inductance connected in series with the diode, independently of the direct or reverse polarity (or polarization) conditions of the latter. At high frequencies, i.e. from about 30 GHz upward, the impedance of said inductance reaches an ever increasing value, for instance 25 to 50 Ohms at 95 GHz, thus causing the impedance of the diode to increase considerably, which is contrary to the aim to be achieved. Thus such inductance has undesirable effects at elevated operating frequencies, and its presence renders the commutating or switching diode unsuitable, since it no longer exerts its function of isolating the hyperfrequency signals. It thus becomes necessary, when operating at high frequencies, to compensate the series inductance of the diode.
This technical problem related to the excessively high inductance of the metallic beams under high frequency conditions also arises with respect to a Schottky beam-lead diode which presents a structure identical to that of the above described PIN diode, but comprises a metal/semiconductor junction and is used as a detecting and mixing diode, wherefrom results the necessity of compensating the said inductance.